Hi I recently started using my S4 again as a back up phone after updating it to Lollipop. However when I insert a SIM card it does not appear to be working in the phone. When I take the SIM card out it says no SIM inserted. When I insert it, the no SIM error goes away yet calls do not work and in the network check it says no SIM available. Please help me solve this issue and figure out whether it is a hardware or software issue. Thank you